Mystery Airplane: April 2014

Frank Piasecki founded PV Engineering in 1941. His experimental PV-2 helicopter appeared in April 1943, followed by NACA awarding him Helicopter Pilot Certificate No. 1. The H-21 (the May 2011 Mystery Plane) was followed by the PV-14, which led to the Navy's HUP "Retriever" and the Army's H-25 "Army Mule." Powered by a 550 hp R-975 radial engine, the HUP had a maximum speed of 108 mph and a range of 360 miles. Its useful load with two pilots, was 1650 pounds, four to seven passengers or three stretchers. Nicknamed "the hupmobile" and "the shoe," 339 were manufactured.

In 1954, the Royal Canadi...